[PATCH v5] staging: rtl8192u: add error handling for usb_alloc_urb

From: Zhouyang Jia
Date: Sat Jun 16 2018 - 11:48:10 EST


When usb_alloc_urb fails, the lack of error-handling code may
cause unexpected results.

This patch adds error-handling code after calling usb_alloc_urb,
and fixes memory leaks in error paths.

Signed-off-by: Zhouyang Jia <jiazhouyang09@xxxxxxxxx>
---
v1->v2:
- Fix memory leak.
v2->v3:
- Release memory in error path.
v3->v4:
- Use kcalloc instead of kmalloc_array.
v4->v5:
- Free priv->rx_urb[i]->transfer_buffer and priv->oldaddr.
---
drivers/staging/rtl8192u/r8192U_core.c | 34 ++++++++++++++++++++++++----------
1 file changed, 24 insertions(+), 10 deletions(-)

diff --git a/drivers/staging/rtl8192u/r8192U_core.c b/drivers/staging/rtl8192u/r8192U_core.c
index 7a0dbc0..9413f29 100644
--- a/drivers/staging/rtl8192u/r8192U_core.c
+++ b/drivers/staging/rtl8192u/r8192U_core.c
@@ -1639,8 +1639,9 @@ short rtl8192_tx(struct net_device *dev, struct sk_buff *skb)
static short rtl8192_usb_initendpoints(struct net_device *dev)
{
struct r8192_priv *priv = ieee80211_priv(dev);
+ int i;

- priv->rx_urb = kmalloc(sizeof(struct urb *) * (MAX_RX_URB + 1),
+ priv->rx_urb = kcalloc(MAX_RX_URB + 1, sizeof(struct urb *),
GFP_KERNEL);
if (!priv->rx_urb)
return -ENOMEM;
@@ -1649,12 +1650,12 @@ static short rtl8192_usb_initendpoints(struct net_device *dev)
for (i = 0; i < (MAX_RX_URB + 1); i++) {
priv->rx_urb[i] = usb_alloc_urb(0, GFP_KERNEL);
if (!priv->rx_urb[i])
- return -ENOMEM;
+ goto out_release_urb;

priv->rx_urb[i]->transfer_buffer =
kmalloc(RX_URB_SIZE, GFP_KERNEL);
if (!priv->rx_urb[i]->transfer_buffer)
- return -ENOMEM;
+ goto out_release_urb;

priv->rx_urb[i]->transfer_buffer_length = RX_URB_SIZE;
}
@@ -1666,9 +1667,13 @@ static short rtl8192_usb_initendpoints(struct net_device *dev)
void *oldaddr, *newaddr;

priv->rx_urb[16] = usb_alloc_urb(0, GFP_KERNEL);
+ if (!priv->rx_urb[16])
+ goto out_release_urb;
+
priv->oldaddr = kmalloc(16, GFP_KERNEL);
if (!priv->oldaddr)
- return -ENOMEM;
+ goto out_release_urb;
+
oldaddr = priv->oldaddr;
align = ((long)oldaddr) & 3;
if (align) {
@@ -1686,17 +1691,26 @@ static short rtl8192_usb_initendpoints(struct net_device *dev)
priv->pp_rxskb = kcalloc(MAX_RX_URB, sizeof(struct sk_buff *),
GFP_KERNEL);
if (!priv->pp_rxskb) {
- kfree(priv->rx_urb);
-
- priv->pp_rxskb = NULL;
- priv->rx_urb = NULL;
-
DMESGE("Endpoint Alloc Failure");
- return -ENOMEM;
+ goto out_release_oldaddr;
}

netdev_dbg(dev, "End of initendpoints\n");
return 0;
+
+out_release_oldaddr:
+ kfree(priv->oldaddr);
+
+out_release_urb:
+ for (i = 0; i < (MAX_RX_URB + 1); i++) {
+ if (priv->rx_urb[i]) {
+ kfree(priv->rx_urb[i]->transfer_buffer);
+ kfree(priv->rx_urb[i]);
+ }
+ }
+ kfree(priv->rx_urb);
+ priv->rx_urb = NULL;
+ return -ENOMEM;
}

#ifdef THOMAS_BEACON
--
2.7.4